Keith Poole, who I have mentioned here before, has developed a specialty of sorts measuring the degree of political polarization in the U.S.
His general thesis is that our politicians are a lot more polarized than we are.
But he also has some interesting observations about the contrasting polarization of the two major parties. In a previous post, I provided charts showing that Republicans have moved further away from the center than Democrats.
Now Poole has developed a chart showing that President Obama is the most moderate Democratic president since the end of World War II, while President George W. Bush was the most conservative president in the post-war era.
Poole made these observations based on Congressional roll call votes on which the president clearly indicates his support or opposition. For a fuller explanation, see Poole's posting here.